Hi @Fallenspartan.
Hope you’re doing great 
I’m sorry you’re having this EAC issue playing Lost Ark, thank you for letting us know that you tried to fix this problem, when you have a chance can you try this troubleshooting please:
Try adding Windows firewall exceptions manually:
Press Windows + R, type “firewall.cpl” into the Run window, and then press Enter.
Click Allow an app or feature through Windows Firewall and then click Change settings.
Look for the game in the list of allowed apps and features. If it’s present, make sure it’s checked, and that both the Private and Public columns have a check mark. If the game is missing from the list, you must add it.
Click Allow another app…, locate and select LostArkLauncher.exe, and then click Add.
Once you’ve done that, make sure that Lost Ark has check marks under both the Private and Public columns.
If the issue persists, here’s some more stuff we can try:
Troubleshooting Lag and Connectivity Issues - Support | Amazon Games
Hopefully this troubleshooting works for you, if the issue still persist, we like to take a closer look into this issue with you, when you have a chance, please use the link here to speak with our Customer Service team:
Contact Us | Amazon Games
Please make sure to have the DxDiag ready once you reach support, you can pull it following this steps:
DxDiag report:
Go to Windows Start search bar and type dxdiag.
Click on dxdiag.exe.
When green progress bar goes away, select Save All Information and save the file to their desktop.
Also please make sure you send this link to the agent so we can help you to investigate this issue, also give them all the information needed. And please let me know how was it!
Cheers! 
